The invention concerns an Internal Combustion Engine with a supercharger operated by means of exhaust energy for the compression and transport of an air charge. The supercharger has at least one exhaust chamber and one air charge chamber which are separated from each other by a partition. The exhaust chamber is equipped with an exhaust inlet and an exhaust outlet, and the air charge chamber with an air charge inlet and an air charge outlet. In the gas circuit connected to the exhaust inlet is a system for the timed introduction of exhaust into the exhaust chamber. The supercharger according to this invention is also powered by a linkage responsive to rotation of the engine crankshaft. A theoretically known internal combustion engine of this type is especially intended for internal combustion motors for power vehicles.
Today, customary with the charging of Diesel motors, for which almost exclusively exhaust driven superchargers are used, three areas of operation are observed.
(1) Area of lower speed of rotation, whereby the exhaust driven supercharger transports too little air; PA1 (2) A median speed of rotation area, in which air requirement and air available are both more or less even; PA1 (3) Area of high speed of rotation, in which air supplied by the exhaust driven supercharger is too high and therefore air or exhaust is blown off.
Besides, there is the problem that with sudden load increase, the exhaust supercharger needs several seconds--up to 7 or 8 seconds for car motors--in order to build up the necessary load pressure. Also, exhaust driven superchargers usually have a lower compression ratio than normally aspirated motors in order to provide the same compression pressure and temperatures at loading. Starting of Diesel engines with exhaust driven superchargers is different, because the compression pressures in low-power conditions are low and the necessary ignition temperature is difficult to achieve. Therefore, starting assistance for these motors is necessary.
It is further known, that especially with car and stationary motors that a high degree of energy is lost in the exhausts. The recovery of workable energy from the exhaust of small combustion power machines, especially cars has up to now not been done due to reasons of cost. If one uses mechanical direct driven superchargers for Diesel motors, then at low speeds of rotation, the necessary air supply is provided, but at median and higher speeds of rotation the supply of air is too high. Altogether there is the disadvantage that the power for the start of the supercharger must be taken from the power output of the internal combustion engine. Relief is created here in such a way that either the mechanical supercharger at median or higher speeds of rotation is switched off through coupling, or a gear unit for the alteration of the transmission gear is introduced.
With Otto cycle (gasoline) motors, the situation is similar, only that the starting difficulties with the exhaust supercharged motors are not present.
In summary it is determined, that for the supercharging of combustion motors the presentation of exhaust energy at low speeds of rotation is too low and at high speeds of rotation is too high. If one wants to use instead of an exhaust driven supercharger a mechanical driven one, which delivers at low speeds of rotation the needed supercharging energy, then one has to use mechanical output energy for this. The increase of performance through recovery of workable energy out of the exhaust energy is now too expensive, especially for smaller motor vehicles.
It has therefore theoretically been recommended to create an internal combustion engine of the aforementioned type, in which the power transfer can become effective between the piston of a supercharger and the mechanical output of the internal combustion engine in both directions, so that from under a particular load level mechanical energy can be transferred from an output shaft of the internal combustion engine to the supercharger and from this to the air charge, and at high engine power levels energy is taken from the exhaust gases and transferred to the output shaft of the internal combustion engine. With this process, one can in a cost advantageous way, with a single appliance, take energy from the output shaft of the internal combustion engine, as well as out of the exhaust of this internal combustion engine, to effect the supercharging of the internal combustion engine, and also transfer the exhaust energy to the output shaft.
A positive displacement supercharger which should be drivable mechanically as well as being drivable by exhaust gas energy transfers energy from the expansion of the exhaust gas onto the output shaft of the internal combustion engine causing various air regulation problems.
The regulation of the air amount supplied to the engine can be reached with mechanical as well as with exhaust driving of the supercharger through adjustment of the supercharger piston stroke. In exhaust driven operation the natural exhaust impulses control the cycle frequency of the supercharger adapts to the ignition frequency of the motor. If a pulse generator installation is used, over which exhaust impulses out of storage are passed to the supercharger, the time frequency of the pulse generator can be altered. By mechanical operation there is however the possibility also to alter the start speed of the supercharger.
If the supercharger is operated as an exhaust gas driven motor, an effective usage of the exhaust energy can only be obtained, when the exhaust impulses timely coincide with the output shaft of the motor specified simultaneous movement of the supercharger piston, as otherwise the exhaust energy would have an effect to act as a brake, that is to say energy consuming.
Installations for speed regulation or stroke adjustment for the mechanical supercharger output are complicated and expensive especially for the application of the explained process for small power vehicle motors.
The invention is based on the concern to create a simple and cost advantageous and at the same time reliable construction, which enables the adaption of the mechanical supercharger movement to the timing of exhaust impulses, and which allows also, to carry out for the mechanical supercharger operation an especially simple and effective regulation of the air charge amount.
The solution of the task is such that the power transfer installation shows a device for the alteration of the phase position between start and output side.
In this way the movement of the supercharger piston and the output shaft of the motor can be coordinated, so that through the energy from the exhausts in the exhaust chamber released energy supports the movement of the piston and in this way is carried over onto the output shaft of the internal combustion engine.
As has been proved theoretically by usage of a mechanical displacement supercharger the slightest amount of energy is required, if the air from the supercharger flows directly into the motor cylinder. Through the alteration of the phase position between the driving and driven gears of the supercharger gears train the synchronization between the engine and supercharger can be altered. The invention enables therefore with comparatively simple and cost advantageous construction not only the optimal adjusting of supercharging movement on the exhaust impulses in the exhaust driven operation, but also the otherwise only expensively to be solved air amount regulation in mechanical supercharger operation, whereby the initially explained, up to now only theoretically mentioned operation type is also practically feasible, namely especially also for small power vehicle motors, where this has special meaning.
An advantageous development consists, that the power carry-over installation can be interrupted what for instance can be done through coupling.
An especially advantageous development consists, in that the power carry-over installation includes a belt drive, in which the proportion of the belt length between driving and loose belt strand is adjustable.
The installation for the timed charging and exhaust chamber can be the exhaust valve or else the exhaust valves of the internal combustion engine. One can however install a pulse generator valve, whereby this pulse generator valve can have an exhaust collector or buffer interposed.
For a supercharger operation type with especially minimal expenditure of energy exists an advantageous development in such a way that the air transport volume of an air charge chamber of the supercharger corresponds to the desired air charge amount of the engine cylinders.
On hand of the new following description of an in the drawing presented performance example of the invention this is explained more closely. It shows: